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Entry   Cavity Lock and Finess measurment , posted by Manar Amer at ThomX igloo about lasers and optics | detectors and electronics 6x
    Reply   Cavity Lock and Finess measurment , posted by Manar Amer at ThomX igloo about lasers and optics | detectors and electronics 
       Reply   Cavity Lock and Finess measurment , posted by Manar Amer at ThomX igloo about lasers and optics | detectors and electronics Finesse_Fit.png
          Reply   Cavity Lock and Finess measurment , posted by Manar Amer at ThomX igloo about lasers and optics | detectors and electronics apercu_03.jpgBras_manipulateur.jpg
Message ID: 125     Entry time: Thu Feb 3 18:59:10 2022     In reply to: 121     Reply to this: 126
 Author: Manar Amer 
 Status: Fixed 
 Type: report 
 Category: lasers and optics | detectors and electronics 
 Location: ThomX igloo 
 Title: Cavity Lock and Finess measurment  

to measure the Finesse, instead of having 2x EOM for the PDH and for the modulation sweep, I simply used 2x generators coupled with DC-blocks to a T connector (SMA) screwed directly on the EOM input.

as the transmission signal is fluctuating, it is not easy to have a good fit of the Airy peak.

if I measure the width at half of the maximum of the peak, I found roughly 10kHz instead of the awaited 2kHz... :-(

one needs a better evaluation with a more stable transmission signal and also to be sure that the L-shape metal piece (used to remove high order modes) does not introduce some losses and then reduce the Finesse...

Manar Amer wrote:

This morning, me and Ronic managed to obtain the FSR and image of the finesse which is to be analyzed.

Adding:

  • Beam Image at P4 propagation, no lens is added.
  • Image of the Finesse on Oscilloscope

more information to be included later

Will continue in the afternoon .

 

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